/Engine/Source/Runtime/Slate/Public/Framework/Text/ShapedTextCache.h
Try and find an existing overflow shaped text instance, or add a new entry to the cache if one cannot be found. The overflow sequence is used to replace characters that are clipped.
The shaped text instance
FShapedGlyphSequenceRef FindOrAddOverflowEllipsisText ( const float InScale, const [FShapedTextContext](API\Runtime\Slate\Framework\Text\FShapedTextContext) & InTextContext, const [FSlateFontInfo](API\Runtime\SlateCore\Fonts\FSlateFontInfo) & InFontInfo )